Using data from the Taiwanese death registry and the census of victims of the poisoning, we compared mortality at 28 years after the PCB exposure occurred. For the first time, there was excess mortality from cancer, specifically stomach cancer. This adds consistency to the evaluations made by several public health organizations that these chemicals are carcinogenic for humans. There was also an unexpected excess of deaths from systemic lupus, which has not been seen in other cohorts exposed to similar chemicals.